Cigarette with coated wrapper ventilation flaps

ABSTRACT

A ventilated cigarette employing one or more flaps defined by slit patterns in the wrapper thereof and which flaps are adapted to move away from the wrapper encircling course when the cigarette is puffed to admit ventilating or diluting air streams to the tobacco cylinder which is made with the slit pattern fashioned to extend generally transverse of the article longitudinal axis to provide flap movement about a hinge line disposed generally parallel to said longitudinal axis. The slit pattern can be made the the form of an X, a V or other suitable configuration. The article further has a coating of an airimpervious normally rigid material on either the inner or outer surface of the wrapper in covering and encircling expanse about each slit pattern and associated flap to normally constrain or hold the flap in the encircling wrapper course. When the cigarette has been smoked to an extent that ventilation is advantageous or desirable, the material responsive to the presence of heat from warm smoke and the burning coal or to the ingredients of tobacco smoke becomes softened and constraint on the flap is released to permit the circular tension in the wrapper to cause the flap to move away from the wrapper encircling course and admit ventilation air.

[ CIGARETTE WITH COATED WRAPPER VENTILATION FLAPS William K. Stephens,Jr., Mechanicsville, Va.

[75] Inventor:

[73] Assignee: Philip Morris Incorporated, New

York, NY.

[22] Filed: May 3, 1972 21 App]. No.: 250,064

[52] US. Cl. 131/9, 131/10 A, 131/15 B [51] Int. Cl A2411 01/00 [58]Field Of Search 131/9, 8 R, 15 R,

[56] 8 References Cited UNITED STATES PATENTS 2,754,828 7/1956 Swain131/15 B X 2,841,153 7/1958 Pelletier 131/15 B X 3,020,915 2/1962 Miller131/15 B X 3,054,409 9/1962 Miller..... 131/15 B UX 3,395,714 8/1968Kahane... 131/9 3,473,535 10/1969 Stahly..... 131/15 B X 3,511,2475/1970 Tamol 131/15 B 3,526,904 9/1970 Tamol 131/15 B FOREIGN PATENTS ORAPPLICATIONS 696,911 11/1964 Canada 131/15 B 1,914,963 10/1970 Germany131/8 R [111 3,739,785 June 19, 1973 Primary Examiner-Robert W. MichellAssistant ExaminerGeorge M. Yahwak Attorney-Elmer R. Helferich, NormanN. Schuttler. John T. Kelton et al.

[57] ABSTRACT A ventilated cigarette employing one or more flaps definedby slit patterns in the wrapper thereof and which flaps are adapted tomove away from the wrapper encircling course when the cigarette ispuffed to admit ventilating or diluting air streams to the tobaccocylinder which is made with the slit pattern fashioned to ex tendgenerally transverse of the article longitudinal axis to provide flapmovement about a hinge line disposed generally parallel to saidlongitudinal axis. The slit pattern can be made the the form of an X, aV or other suitable configuration. The article further has a coating ofan air-impervious normally rigid material on either the inner or outersurface of the wrapper in covering and encircling expanse about eachslit pattern and associated flap to normally constrain or hold the flapin the encircling wrapper course. When the cigarette has been smoked toan extent that ventilation is advantageous or desirable, the materialresponsive to the presence of heat from warm smoke and the burning coalor to the ingredients of tobacco smoke becomes softened and constrainton the flap is released to permit the circular tension in the wrapper tocause the flap to move away from the wrapper encircling course and admitventilation air.

13 Claims, 11 Drawing Figures Patontud June 19, 1913 3,139,735

3 Sheets-Sheet 1 TPM TPM

Patented June 19, 1973 3,739,785

3 Sheets-Sheet 8 0- CONTROL COATED FLAPS I I I I I I I l I I I I I I|2345e7a9|ou|z|3|4 PUFF. NO.

CIGARET "Y" 6 PUFF. NO.

CIGARET "z" I 2 3 4 5 6 7 8 9 IO II I2 PUFF. N0.

Patented June 19, 1973 3 Sheets-Sheet 5 FIG. 9

FIG. /0

CIGARETTE WITH COATED WRAPPER VENTILATION F LAPS BACKGROUND OF THEINVENTION The desirability of delayed ventilation to control TPMdelivery during later puff stages during smoking of a cigarette isdescribed, e.g., in U. S. Pat. Nos. 2,992,647; 3,511,247 and 3,526,904.The term profile is used to describe the plot of delivery (usually totalparticulate matter or TPM) with each puff versus the puff number.Because the profile of a conventional cigarette shows a steep increasewith later puffs, it is desirable to have ventilation to reduce deliveryat that stage, but to have little or no ventilation to diminish flavorat the early puffs.

Certain patents have disclosed means of ventilating cigarettes to reduceTPM delivery by using openings in the wrapper to provide a point ofentry of ventilation air to the cigarette. Some patents discloseformation of slits in the wrapper to give flaps which open by beingdrawn inward with the puff on the cigarette, e.g., U. S. Pat. Nos.3,057,360 and 3,020,915. U. S. Pat. No. 3,054,409 causes the slits toremain open by reinforcing them with a stiffening coating while in U. S.Pat. No. 3,310,055 it is taught to reinforce wrapper perforations byprinting with a special ink or other material on the wrapper adjacentthe openings.

The aforementioned types of cigarettes are all effective for thepurposes enumerated but they are difficult products to make uniformlyand unvaryingly in the way that modern commercial standards demand athigh production line speeds, especially in respect of controllingopening size and insuring positive opening movement of the flaps whendesired.

SUMMARY OF THE INVENTION The present invention is concerned with acigarette which employs ventilation features as a means for controllingthe TPM delivery profile of the smoke delivered to the smoker. It ismore particularly concerned with ventilation type cigarettes wherein thepaper wrapper of the cigarette which is drawn tightly against thetobacco for holding it under radial constraint thereby producing acircular tension in the wrapper, is provided with an arrangement thereinof one or more slits of predetermined pattern and at predeterminedpositioning from the smoking or lighting end of the cigarette which slitpatterns define corresponding flaps in the wrapper which are movableaway from the encircling wrapper course when the cigarette is puffed toadmit dilution air flow to the cylinder of tobacco. In accordance withthe present invention each flap in the cigarette wrapper is maintainedin a normally constrained position disposed in the encircling wrappercourse by means of an air-impervious normally rigid material coatingapplied preferably at the inner side of the wrapper with the coatingbeing disposed in a covering and encircling expanse around each slit andassociated flap. The material is such as to be softenable responsive tothe presence of heat from warm smoke and the burning coal of thecigarette or responsive to the action of smoke ingredients so that afterthe cigarette has been smoked to a predetermined distance, the materialsoftens and permits the flap or flaps to move away from the wrapperencircling course either inwardly or outwardly thereof under the impetusof the circular tension in the wrapper and to thereby admit ventilationair. The arrangement of flaps in the wrapper is such that more arelocated near the mouth end than the smoking end so that increasingmeasures of ventilation air will be admitted in the later stage puffswhen the TPM levels show a steep upwardly incline.

For the purposes of the present invention various materials can beemployed as the coating, as for example, hot melt adhesives, as well asvarious types of resin materials.

In accordance with the present invention the number and size of the slitpatterns and associated flaps provided in the wrapper will be providedon the basis of the desired degree of ventilation as well as the smokingcharacteristics of the ciagarette. Generally each slit pattern is formedto have a total slit length of between 2 to 6 mm. and the slits can bein various forms, as for example, in the fashion of an X, V or suchother configuration as extends generally transverse of the longitudinalaxis of the article to provide movement of the associated flaps about ahinge line disposed generally parallel to said axis.

In accordance with the present invention the slit patterns andaccordingly the therewith defined flaps in the paper wrapper can bearranged in extending longitudinal array in the wrapper on a centerlinespacing of about 5 mm. between adjacent ones of the slit patterns.Further, the slit patterns can be arranged in side-byside parallelarrangement extending in two or more rows longitudinally of the wrapper,each slit pattern being aligned with at least one other slit pattern.The coating applied on and around each slit pattern associated flappreferably should be applied in a range of about 3 to about 10 micronsthick.

The invention accordingly comprises the features of construction,combination of elements and arrangement of parts which will beexemplified in the constructions hereinafter set forth and the scope ofthe invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS A fuller understanding of the natureand objects of the invention will be had from the following detaileddescription taken in conjunction with the accompanying drawings inwhich:

FIG. 1 is a perspective view of a cigarette embodying flaps in thewrapper thereof which are movable away from the wrapper encirclingcourse during smoking to admit ventilation air streams to the tobaccocylinder, the flaps being held constrained by a heat and/or tobaccosmoke softenable coating on the wrapper in accordance with theprinciples of the present invention until the cigarette has been smoke apredetermined distance.

FIG. 2A is an enlarged fragmentary sectional view through the tobaccocylinder of the cigarette shown in FIG. 1, the wrapper ventilation flapsbeing depicted in constrained closed position wherein they are held bythe coating of normally rigid but heat and/or tobacco smoke softenablematerial.

FIG. 2B is the same as FIG. 2A except it shows the moved position of theventilation flaps following softening of the materialf FIG. 3 is aperspective view of a somewhat different FIG. 4 is a plan view of thewrapper embodied in the cigarette shown in FIG. 3, the inner surface ofthe wrapper facing the viewer. I

FIG. 5 is a graph illustrating the delivery profile of a cigarette ofthe type depicted in FIG. 1 as compared with a cigarette not providedwith ventilation flaps.

FIGS. 6 and 7 are graphs illustrating the respective delivery profilesof FIG. 3 cigarettes in which the heat and/or tobacco smoke softenablematerial with which the wrappers were coated is a hot melt adhesive, and

1 greater the number of slit patterns and associated flaps,

greater dimension transversely of the smoking article s longitudinalaxis than in the direction of such axis.

Throughout the following description like reference numerals are used todenote like parts in the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the cigarette10 depicted in FIG. 1, it includes a cylinder of tobacco l2 enclosed ina paper wrapper l4 and having a filter element 16 connected at the mouthend thereof in conventional manner. The wrapper 14 encircles the tobaccocylinder 12 and is drawn tightly thereagainst and held in securementalong overlapped longitudinal edges 115, 117 for holding the tobaccounder radial constraint, which condition produces a circular tension inthe wrapper. The wrapper 14 is provided with an arrangement of slitpatterns 18 which as can best be seen in FIGS. 2A and 28 form and definea corresponding pattern of flaps 22 in the paper wrapper which as willbe explained later lie in the encircling course of the wrapper beingheld in such disposition by a coating of material to be described later,but which flaps when the ciagarette is puffed, can move inwardly oroutwardly of the wrapper encircling course to provide openings throughwhich dilution streams of ventilating air are admitted to the tobaccocylinder. The slit patterns can be formed in various arrangements in thewrapper depending upon the level of dilution desired as well as thepoint at which such dilution is to first occur. Further, the slitpatterns should be arranged or fashioned in the wrapper to extendgenerally transversely of the longitudinal article to provide formovement of the associated flaps about a hinge line disposed generallyparallel to said axis. In this manner, the circular tension in wrappercan be employed to bias the flap away from the wrapper encircling coursewhen constraint on the same is released upon removal of theabove-mentioned coating of material from the wrapper. Advantageously,the slit pattern is fashioned in the form of an X and preferably wherethe X is of relatively greater dimension transversely of the greater thedegree of ventilation provided. In the depicted embodiment, the firstslit pattern 18, and accordingly associated ventilation flaps 22, islocated about 22 mm. from the lighting end of the cigarette with theremaining slit patterns being spaced longitudinally downstream therefromon a centerline spacing of about 5 mm. The distance between the lastslit pattern 18 and the filter end of the tobacco cylinder is about 15mm.

In accordance with the present invention the wrapper is further providedwith a coating 20 of a normally rigid material preferably disposed atthe inner surface of the wrapper in covering and encircling expanseabout each slit pattern 18 and flap 22 defined thereby. The material,however, is a type which becomes softened responsive to heat from theburning coal or smoke of the cigarette when smoked, or which is softenedresponsive to exposure to certain ingredients of tobacco smoke, e.g.,moisture. The material as seen in FIG. 2A normally maintains the flaps22 in the encircling course of the wrapper and thereby prevents dilutionof the cigarette until a predetermined point during the smoking of thesame. When the cigarette has been smoked from the lighting end a certaindistance down to a location near the first slit and flap group, theaction of the tobacco smoke and/or heat of the advancing coal will havesoftened the material coating 20 sufficiently to release the axis sothat the circular tension in the wrapper will move the flap away fromthe wrapper encircling course to admit dilution air. The manner in whichthe flaps 22 move following softening of the material 20 is depicted inFIG. 2B. The present invention also provides as described earlier thatthe coating of air impervious normally rigid material can be on theouter surface of the wrapper. Thus, as shown in FIG. 9, the wrapper 134is provided with a coating of material 144 on the outer wrapper surface162, the slit pattern thus being disposed under the coating in thefinished smoking article.

Materials suitable for use in the cigarette of the present inventioninclude microcrystalline wax; Polyox" polyoxyethylene resins (UnionCarbibe Corp.); blends of Penna. Industrial Chemical Co.s Piccotexpetroleum hydrocarbon resins as follows: I00 with equal part refinedparaffin wax (Gulf Oil Co.), LC with equal part P2X wax blend (AlexanderSaunders & Co.); or any hot-melt adhesive resin of melting point from130 to F., preferably light in color.

The coating as indicated is preferably applied to the inner side of thewrapper although it may advantageously be applied to the outer side ofthe same, with such coating being applied in any suitable manner. For

. example, the coating can be printed on with a conventional roller setor the printing can be combined with the slitting of the wrapper in asingle operation in which the die that forms the slit patterns 18 hasadjacent the die projection, a land formation which will print thecoating of material simultaneously on the wrapper surface. In thismanner the registration between the slits and the material coating willalways be accurate and uniform. Further, the coating 20 holds the flaps22 in the wrapper in proper positioning to insure that the flaps willnot be affected by the circular tension produced in the wrapper when thelatter is tightly wrapped around the cylinder of tobacco until thedesired time at which the coating is softened to release the flapsconstraint and allow such tension to bias the flaps outwardly of thewrapper encircling course.

The coating 20 of material applied to the wrapper can be applied to athickness of about 3 to about mi- 5 and flaps defined by the slitpatterns. On the other 10 hand, as shown in FIGS. 3 and 4, the coatingcan be applied as a relatively large contiguous layer which covers andencircles all of the slit patterns in the wrapper.

The cigarette 30 shown in FIG. 3 includes a tobacco cylinder 32 having apaper wrapper 34 enclosing a mass of tobacco as well as a filter element36 at the mouth end. The wrapper 34 as best seen in FIG. 4 is providedwith an arrangement of slit patterns 40 which each define acorresponding arrangement of flaps 42, all of which are covered andencircled by a coating 44 of normally rigid but heat and/or tobaccosmoke softenable material as described above. In the FIG. 3 and 4cigarette embodiments, the slit patterns are arranged, for example, tostart at 15 mm. from the lighting end of the cigarette with the slitpatterns being longitudinally spaced on 5 mm. centers with the slitpatterns nearest the mouth end of the wrapper being approximately 10 mm.from that wrapper end. A total of four longitudinally disposed rows areprovided with the slit patterns in each row being in longitudinalside-by-side array with at least some of the slit patterns in other ofsaid rows as shown in FIG. 4.

The invention can be further understood from the following examples:

Example 1 A slow burning cigarette paper (as supplied by Sutliff TobaccoCompany, Richmond, Virginia, for use with their RYO cigarette maker) wasslit according to the pattern of FIG. 1. The inner side of the paper wasthen coated as shown with a very thin film of microcrystalline wax(150F. melt). These papers were used to make hand-made cigarettes from acommercial filler with the maker. Similar cigarettes were made ascontrols without slits or coating. Filters of cellulose acetate 45 tow,20 mm., were attached to both sets of rods. The cigarettes were smokedby machine and puff-by-puff measurement of particulate delivery (TPM)was made. The comparative results shown in Table I below and in FIG. 5show the leveling effect of the coated flaps.

Paper as used in the preceding example was slit in the pattern shown inFIG. 3 with slits 2 1% X 2 1% mm. approx. 5 mm. apart. The entire areaof the slits was coated with about 3 microns of either high-meltadhesive type 34-3003 supplied by National Starch Co.

(Cigarette Y) or Polyox 3000 supplied by Union Carbide Corp. (CigaretteZ). Cigarettes were handmade with these wrappers, using a commercialfiller, 1.0 g., and attaching a cellulose acetate filter, 3.4denier/46000 total, 25 mm. long. When these cigarettes were smoked bymachine for puff-by-puff analysis, they showed very level deliveryprofiles in both instances. Table II below and FIGS. 6 and 7 show thegenerally leveled profiles of Cigarettes Y and Z, respectively.

TABLE II TPM mg/puff Puff No. Cigarette Y Cigarette Z 1 1.40 1.30 2 0.751.47 3 0.93 1.39 4 1.04 1.62 5 1.23 1.62 6 1.14 1.51 7 1.07 1.82 8 1.281.89 9 1.13 1.85 10 1.36 1.90

The cigarette shown in FIG. 8 is substantially the same as that earlierdescribed except the slit pattern 158 used in the wrapper 156 is in theshape of a V, extending transversely of the cigarette longitudinal axis.When the cigarette 150 has been smoked to a predetermined extent, heatfrom the burning coal 152 and smoke will soften the coating 154 at theinner surface of the wrapper 156 and the circular tension in the wrapperwill cause the flap 160 to move away from the wrapper encircling courseand admit dilution air stream flow to the tobacco cylinder. As smokingcontinues, the succeeding ones of the flaps 160 will open in progressionto continue dilution, etc.

What is claimed is:

1. In a smoking article an elongated cylinder of tobacco,

a wrapper encircling said cylinder of tobacco and drawn tightlythereagainst and held in securement along overlapped longitudinal edgesof said wrapper for holding said tobacco under radial constraint whichproduces a circular tension in said wrapper, said wrapper having innerand outer surfaces, said wrapper further having therein an arrangementof one or more slits of predetermined pattern, each slit patterndefining a corresponding flap in said wrapper, said flap being radiallymovable inwardly and outwardly from the encircling wrapper responsive topuffing of said smoking article to admit dilution air flow to saidcylinder of tobacco, each slit pattern being fashioned in said wrappersuch as to extend generally transverse of the longitudinal axis of saidarticle to provide for movement of the associated flap about a hingeline disposed generally parallel to said longitudinal axis; and

a coating of an air-impervious normally rigid material on said wrapperat one side thereof and extending in covering and encircling expanseabout each said slit pattern and the flap defined by said slit patternto normally constrain said flap in the encircling wrapper,

said material being further characterized by being selected frommaterials softenably responsive to the presence of heat from the warmsmoke and burning coal of said smoking article or moisture of tobaccosmoke whereby the constraint on said flap is released and the circulartension in said wrapper causes said flap to move away from saidencircling wrapper during the smoking of said smoking article.

2. The smoking article of claim 1 wherein each of the slit patterns isin the form of an X.

3. The smoking article of claim 2 wherein each of said slit patterns isof relatively greater dimension transversely of the article slongitudinal axis than in the direction of said axis.

4. The smoking article of claim 1 wherein the slit pattern is in theform of a V extending transversely of the articles longitudinal axis.

5. The smoking article of claim 1 wherein said material is a hot meltadhesive.

6. The smoking article of claim 5 wherein said material is amicrocrystalline wax.

7. The smoking article of claim 1 wherein said material is apolyethylene resin.

8. The smoking article of claim 1 wherein said material is one having amelting point in the range of about 8 F. to about F.

9. The smoking article of claim 8 wherein at least some of said slitpatterns are in side by side parallel arrangement with others of saidslit patterns on said wrapper.

10. The smoking articles of claim 8 wherein the total slit length ofeach of said slit patterns is in a range of about 2 mm. to about 6 mm.

1 1. The smoking article of claim 1 wherein said material coatingthickness is in the range of about 3 to about 10 microns.

12. The smoking article of claim 1 1 wherein said material coatingthickness is about 3 microns.

13. The smoking article of claim 1 wherein said wrapper contains pluralslit patterns extending in spaced array longitudinally of said wrapperon a centerline spacing of about 5 mm. between adjacent slit patterns.

1. In a smoking article an elongated cylinder of tobacco, a wrapperencircling said cylinder of tobacco and drawn tightly thereagainst andheld in securement along overlapped longitudinal edges of said wrapperfor holding said tobacco under radial constraint which produces acircular tension in said wrapper, said wrapper having inner and outersurfaces, said wrapper further having therein an arrangement of one ormore slits of predetermined pattern, each slit pattern defining acorresponding flap in said wrapper, said flap being radially movableinwardly and outwardly from the encircling wrapper responsive to puffingof said smoking article to admit dilution air flow to said cylinder oftobacco, each slit pattern being fashioned in said wrapper such as toextend generally transverse of the longitudinal axis of said article toprovide for movement of the associated flap about a hinge line disposedgenerally parallel to said longitudinal axis; and a coating of anair-impervious normally rigid material on said wrapper at one sidethereof and extending in covering and encircling expanse about each saidslit pattern and the flap defined by said slit pattern to normallyconstrain said flap in the encircling wrapper, said material beingfurther characterized by being selected from materials softenablyresponsive to the presence of heat from the warm smoke and burning coalof said smoking article or moisture of tobacco smoke whereby theconstraint on said flap is released and the circular tension in saidwrapper causes said flap to move away from said encircling wrapperduring the smoking of said smoking article.
 2. The smoking article ofclaim 1 wherein each of the slit patterns is in the form of an X.
 3. Thesmoking article of claim 2 wherein each of said slit patterns is ofrelatively greater dimension transversely of the article''s longitudinalaxis than in the direction of said axis.
 4. The smoking article of claim1 wherein the slit pattern is in the form of a V extending transverselyof the article''s longitudinal axis.
 5. The smoking article of claim 1wherein said material is a hot melt adhesive.
 6. The smoking article ofclaim 5 wherein said material is a microcrystalline wax.
 7. The smokingarticle of claim 1 wherein said material is a polyethylene resin.
 8. Thesmoking article of claim 1 wherein said material is one having a meltingpoint in the range of about 130*F. to about 180*F.
 9. The smokingarticle of claim 8 wherein at least some of said slit patterns are inside by side parallel arrangement with others of said slit patterns onsaid wrapper.
 10. The smoking articles of claim 8 wherein the total slitlength of each of said slit patterns is in a range of about 2 mm. toabout 6 mm.
 11. The smoking article of claim 1 wherein said materialcoating thickness is in the range of about 3 to about 10 microns. 12.The smoking article of claim 11 wherein said material coating thicknessis about 3 microns.
 13. The smoking article of claim 1 wherein saidwrapper contains plural slit patterns extending in spaced arraylongitudinally of said wrapper on a centerline spacing of about 5 mm.betweEn adjacent slit patterns.